1. Field of the Invention
This invention relates to improvements in a fastening or clamping band used to fasten or clamp and fix a cylindrical member formed of a resilient material or the like to a fixture having a circumferential surface.
2. Related Background Art
A fastening or clamping band formed of band steel is used to fasten or clamp and fix a cylindrical boot, cover or the like to a fixture having a circumferential surface, such as the transmission shaft of a vehicle, for fastening the band, use is made of a fastening tool exclusively designed for such purpose. Prior art examples of the fastening band and fastening tool are shown, for example, in the applicants' Japanese Patent Application No. 76622/1985 (corresponding to U.S. Ser. No. 918,135, now U.S. Pat. No. 4,802,261).
The above-mentioned fastening band according to the prior art is initially made into the form of a loop for tentative fastening in which the opposite end portions thereof are superposed one upon the other, to thereby surround a boot or the like, whereafter the fastening band is deformed by a fastening tool so that the amount of overlap of the opposite end portions becomes greater (that is, the diameter of the loop becomes smaller), and a projection formed on a first end portion which is the outer side in a radial direction of the band and a projection formed on a second end portion which is the inner side in a radial direction of the band are engaged with each other to thereby bring about a regularly fastened state. However, the projection of the first end portion is formed radially inwardly and the projection of the second end portion is formed radially outwardly and therefore, the inward projection of the first end portion must ride over the outward projection of the second end portion when regular fastening is effected from the tentatively fastened state. At this time, it has sometimes happened that the two projections interfere with each other and are pushed down, and the projections can not successfully engage with each other so that the regular fastening becomes difficult or impossible.
Also, the above-mentioned fastening tool has comprised a pair of legs each having an engaging portion at the fore end thereof. The construction has been such that a a force is applied between the legs tending to bring them together or to urge them apart. Therefore, particularly when a fastening band of small diameter is fastened, the distance between the two engaging portions of the fastening tool relative to the diameter of a member to be fastened becomes greater and this has sometimes led to a result that the inner end portion is deformed outwardly. That is, when the fastening force applied to the second end portion is not in the tangential direction thereof but in the direction of chord, the second end portion expands radially outwardly.
Also, in the fastening tool shown in the applicants' Japanese Patent Application No. 5137/1986 (also corresponding to the aforementioned application U.S. Ser. No. 918,135), a discrete member is pivotally connected to the intermediate portion of a body having an engaging portion at the fore end thereof, and an engaging member is pivotally connected to the fore end of said discrete member. During fastening, the entire fastening tool is pivotally moved about the engaging portion of the body. However, since there are two movable portions, these portions are pivotally moved during fastening, and this has sometimes led to a result that the fastening operation cannot be accomplished quickly.